A Metrolinx proposal to extend the underground portion of the Eglinton light rail line to Don Mills Road is coming under fire from a local councillor, who is urging the provincial transit agency to switch to a subway instead.

The proposal, if approved, means that about 12 kilometres — instead of 10 kilometres of the 19-kilometre Eglinton Crosstown — would be underground, which “is not where God intended LRTs to go,” said Don Valley West Councillor John Parker, also a member of the Toronto Transit Commission.

“This is the dumbest way to do it,” he said Thursday. “It’s going to cost more than it should cost, and it’s not going to generate as good a result as we could have had for less money with a different approach.”

Metrolinx is in the midst of collecting public input on a plan to modify an eastern stretch of the Eglinton Crosstown, and scrap two stations in the process. The proposal calls for the tunnelled section of the line to extend from Keele Street across the city and under the Don River before emerging on the surface around Don Mills, instead of Brentcliffe. It would cancel a stop at Leslie Street because of cost, and another at Ferrand Drive.

I would be flattered if anyone even noticed the suggestion

Mr. Parker plans to write to Metrolinx in the coming weeks urging it to build a subway for the underground portion of the line, then a light rail line extension to Kennedy. He said the recent support for a Downtown Relief Line, with Don Mills as a possible terminus, bolsters his case, since a subway could one day extend south to the core, creating a new loop.

“There are so many cans of so many worms being opened [at City Hall],” said Mr. Parker when the question was put to him. “I would be flattered if anyone even noticed the suggestion.”

Contacted by the National Post, Metrolinx is already saying thanks, but no thanks.

“Basically, we’d be reopening the whole LRT versus subway debate,” said Jamie Robinson, a Metrolinx spokesman for the Toronto transit projects, noting that under that scenario, Metrolinx would have to build a subway and LRT connection at Don Mills. “The decision has been made to build light rail transit. Subways aren’t part of the plan.”

Metrolinx disputes Mr. Parker’s assertion that his idea is more affordable because LRT vehicles, designed to run on the surface, are more expensive. On a per-kilometre basis, according to the transit agency, a tunnelled LRT still costs less than a subway.

As for its rationale for the changes, Metrolinx says that Brentcliffe Road is “no longer [a] suitable” place to launch the tunnel boring machines westbound, because new development in the area would require shoring to protect the building foundation. Other complications include traffic disruption over 28 months, slope stability and soil contamination.

It suggests moving the launch site to the southwest corner of Don Mills Road. Doing so would mean moving the Leslie stop underground, at a cost of $80-million, which Metrolinx says it can’t justify with ridership projections.

However, Mr. Robinson said the agency is taking a close second look at the proposal to scrap the Ferrand stop. He said if approved, the changes will not impact the $5.2-billion price tag of the project — even when tunnelling deeper for the section under the Don River — scheduled to be complete in 2020. Metrolinx will collect feedback until Jan. 21.